Breast Anatomy
Breast (aka, mammary gland)
Key reproductive function of the female breast is to produce and transport milk during the hormonally regulated process of lactation.
Review prolactin physiology.
The anatomy of male and female breasts is similar, though adult female breasts are much more developed, especially in those who are pregnant or lactating.
Anatomical context:
Pectoralis major is the large muscle deep to the breast; pectoralis fascia that overlies the muscle.
Retromammary space (aka, bursa) is a potential space between the pectoralis fascia and the breast tissue; it allows for movement of the breast.
External features:
Nipple and areola; the areola is the darker ring of skin that surrounds nipple.
Sebaceous glands lie deep to the areola; they give it a slightly bumpy appearance. During breastfeeding, sebum is released to reduce chaffing and cracking of the skin overlying the nipple.
Internal features:
Fatty matrix
Suspensory ligaments (aka, Cooper's ligaments) weave through the fatty matrix and attach the breast tissue to the pectoralis fascia and the skin.
A lobe is a section of breast tissue between the suspensory ligaments; each breast typically comprises 15-20 lobes.
Glandular tissue comprises lobules, which are collections of terminal duct lobular units: alveoli (which produce milk) that drain into terminal ducts.
Smaller lactiferous ducts drain into main lactiferous ducts; main lactiferous ducts open at the nipple.
The lactiferous sinus provides a small reservoir for milk.
Clinical Correlation:
Breast cancer typically begins within the cells of the lobules or ducts. If cancerous cells travel nearby axillary lymph nodes, they can be distributed to other parts of the body via the lymphatic vessels. Thus, early detection of breast cancer (before it spreads), improves prognosis.
